My bad if I said strength I meant stiffness. While strength is important stiffness is king in CNCs.
I have heard people mention that wood is full of air especially when talking about particle boards, or boards that have been reconstituted. I'm sure Chris will quickly work out what needs to be stiffened up the moment he starts using the CNC.
I made many of my original parts out of plywood just to get started, and later used the CNC to cut fresh parts out of metal. There was a significant difference in rigidity. I had some serious chatter issues back in those early days and the Council was called to check out what I was doing the machine screamed that much.